Rock Star - Level 2

Getting Audio In and Out of a Mobile Phone

 

I've seen this come up in several different situations so I thought it would be worth creating a new post.  When you need to get audio in and out of a mobile phone that has a 3.5mm headphone jack it's important to know that there are two standards for the wiring of these jacks.  Using the wrong adapter can cause all sorts of "weird problems" or it simply won't work depeneding on the phone. 

 

One standard is AHJ or CTIA and the other is OMTP.  While both use a same TRRS plug, the American Headset Jack or Cellular Telecommunications Industry Association standard defines the wiring differently than the Open Mobile Terminal Platform.  

 

For AHJ/CTIA the Tip = Audio Left Out, the First Ring = Audio Right Out, the Second Ring = Ground, and the Sleeve = Microphone In

 

For the OMTP standard the Ground and Microphone In are swapped. In other words, T = Audio Left Out, the first Ring = Audio Right Out, the Second Right = Microphone In, and the Sleeve = Ground. 

 

WpR1r.png

 

This same information applies to the 3.5mm jack on a Lightning Audio adapter or a USB-C Audio adapter. 

 

Again, make sure you are using the right splitter adapter that matches your phone jack. 

 

 

If you want "Loud", then run a piece of sheet metal through a table saw. --Ivan Beaver
KenMitchell Rock Star - Level 2 2019-12-03

2019-12-03

Getting Audio In and Out of a Mobile Phone

 

I've seen this come up in several different situations so I thought it would be worth creating a new post.  When you need to get audio in and out of a mobile phone that has a 3.5mm headphone jack it's important to know that there are two standards for the wiring of these jacks.  Using the wrong adapter can cause all sorts of "weird problems" or it simply won't work depeneding on the phone. 

 

One standard is AHJ or CTIA and the other is OMTP.  While both use a same TRRS plug, the American Headset Jack or Cellular Telecommunications Industry Association standard defines the wiring differently than the Open Mobile Terminal Platform.  

 

For AHJ/CTIA the Tip = Audio Left Out, the First Ring = Audio Right Out, the Second Ring = Ground, and the Sleeve = Microphone In

 

For the OMTP standard the Ground and Microphone In are swapped. In other words, T = Audio Left Out, the first Ring = Audio Right Out, the Second Right = Microphone In, and the Sleeve = Ground. 

 

WpR1r.png

 

This same information applies to the 3.5mm jack on a Lightning Audio adapter or a USB-C Audio adapter. 

 

Again, make sure you are using the right splitter adapter that matches your phone jack. 

 

 

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Rising Star - Level 2

Re: Getting Audio In and Out of a Mobile Phone

@KenMitchell 

I would assume all apples are the same. Are all Androids the same? And which is which?

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Rock Star - Level 2

Re: Getting Audio In and Out of a Mobile Phone

@DaveMorrison  Good question.  i can only speak for what I've seen in North America but both Apple and Android devices here are CTIA.  I did run into an Android phone from Inda that was OMTP but I don't know if that's the norm there or not. 

 

I just wanted to point out that there are two standards. Personally, I carry adapters for both in my bag of tricks. 

 

Ken

If you want "Loud", then run a piece of sheet metal through a table saw. --Ivan Beaver